ads1282-ht: bit toggling in output data
Part Number: ADS1282-HT
Using a single supply of 5V, the reference should also be 5.0V with the Vref+ at 5.0 and the Vref- to gnd? Is this correct? With a differential amplifier driving Vin+ and Vin -, If this voltage went to 0 or 5V can the part tolerate this? Thanks.
It does depend a bit on which voltage you are talking about. A 5V reference is fine with a 5V AVDD. If you use the PGA with a gain of one, then per the input range equation your full scale input range would be +/-2.5V differentially. You must also adhere to the absolute input range though, which is the maximum voltage you can put on a single pin. In this case it would be 3.75V (AVDD-1.25). You can think of this as effectively placing a limit on where you should set your common-mode. A +2.5V differential signal means one input will move +1.25V and one will move down -1.25V. Since the largest voltage you can have on the input is 3.75V, your common-mode should not be greater than 2.5V. Similar logic applies to the low end, but the input range is a little more forgiving allowing you to swing to AVSS + 0.7V. Hope that helps!
Zak Kaye Precision Amplifiers Applications
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Zak Kaye:
Thanks. If the input voltage goes overrange to 0V or 5V, the conversion will not be good but will the part be damaged? The absolute maximum spec for the analog input voltage is VSS-0.3 to VDD+0.3, which in this case is -0.3V to 5.3V.
In reply to Knute Ray:
The part should not be damaged, but as you mention the conversion will be invalid as the PGA goes into saturation. There would be some overload recovery time associated with this as well.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.